Residual dentin thickness in bifurcated maxillary first premolars after root canal and post space preparation with parallel-sided drills

By Pilo R, Shapenco E and Lewinstein I

Date: 04/2008
Journal: JOE

Summary: 

Purpose: To evaluate the RDT of maxillary first premolars after root canal and conservative post space preparation

Materials/Methods:

•N = 97

•Extracted intact maxillary premolars – Free from caries and with closed apices

•Ultrasonically cleansed and soaked in NaOCl 5.25% 

•Teeth radiographed from buccal and messiah surfaces

•Divided into 2 groups: 

1. Bifurcation at the junction of cervical and middle thirds – or in middle third (n=51)

  2. Bifurcation at the junction of middle and apical thirds – or in the apical third (n=46)

•Access cavity prepared with round bur and canal instrumented with K-Files (step-back)

•Post space prepared and Measurements taken throughout root

Most highlighted Results:

•RDT of the mesial aspect was thinner compared to the distal aspect, after all procedures.

•The root canal preparation procedure reduced more dentin in the lingual aspect of buccal root, and buccal aspect of lingual root.

•The RDT of the proximal walls gradually decreased from the coronal to apical slice

•The RDT after RCT in both roots was less than 1 (compromised) in 53% (buccal) and 38% (lingual) of roots

•After post space preparation, values increased to 77% (buccal) and 61% (lingual) roots

Clinical Significance:

•Endodontic treatment and post space preparation with parallel-sided drills jeopardizes root integrity in this aspect due to RDT values of less than the recommended 1 mm When post space preparation is mandatory, it is recommended that the lingual root be used and the buccal root be avoided.

Strength:   Multiple comprehensive measurements, microscopic study

Weakness: sample size